Nighttime Surgeries Twice|as Likely to End in Death

(CN) — If you have the choice — and often we don’t — schedule your major surgery for day rather than night, because patients who go under the knife at night are more than twice as likely to die as those operated on during the day. And patients operated on later in the working day or in the early evening also face a higher mortality risk, according to a group of researchers who presented their findings Monday after a five-year study of postoperative mortality and the timing of surgery at the Jewish General Hospital in Montreal, Canada. Previous studies have identified risk factors that include the patient’s age, the American Society of Anesthesiologists’ overall risk score and emergency status, The team evaluated all surgical procedures between April 2010 and March 2015, and created a database that collected variables about surgical interventions. All elective and emergency surgical cases were included except local anesthesia and ophthalmic cases, since the vast majority of ophthalmic cases are performed under local rather than general anesthesia and not in regular operating rooms. They then divided a standard working day into three time blocks — daytime 7:30 am to 3:29 p.m., evening 3:30 p.m. to 11:29 p.m., and nighttime 11:30 p.m. to 7:29 a.m. The start time of the anesthetic recorded by the nurse was used to determine in which time block the operation began. There were 41,716 elective and emergency surgeries performed on 33,942 patients in 40,044 hospitalizations. Of these, 10,480 were emergency procedures: 3,445 performed in the day, 4,951 during the evening, and 2,084 at night. The researchers found that on the whole, 226 people died after being operated on during the day, 97 in the evening and 29 at night. In cases of emergency surgery, 79 deaths occurred during the day, 95 in the evening and 29 at night. After adjusting for age and ASA scores, the team found that patients operated on at night were 2.17 times more likely to die than those who had surgery during regular daytime working hours. Patients operated on late in the day were 1.43 times more likely to die than those whose surgeries were earlier. “This study demonstrates that late-day and night emergency surgery is associated with higher mortality when factoring in ASA score and patient age. Postoperative 30-day in-hospital mortality rate should include start time of anesthesia, along with other known variables, as a risk factor,” the authors said. Potential causes of the increased risk could include provider fatigue during anesthesia and surgery, delays in treatment — how many operating rooms are available, for instance — overnight hospital staffing issues, or the patients requiring quicker treatment.